1. Field of the Invention
The present invention relates to a drive assembly system. More specifically, the present invention relates to a drive assembly which provides a scanning system with improved images.
2. Description of the Related Art
Radiation images, such as those in radiography and tomography, can be stored in conventional x-ray films or in storage layer radiation screens. Storage layer radiation screens have significant advantages of requiring lower levels of x-ray radiation to produce radiation images, and are reusable after an erasing and sterilization process. A typical storage layer radiation screen can be used for recording images of an object, such as a part of human body, exposed to radiation. The screen is then scanned with stimulating rays, such as a laser beam which causes the phosphors in the screen to emit light in proportion to the amount of radiation absorbed by the portion of the screen being scanned. The light emitted from the screen is then detected and converted into an electrical signal. The electrical signal is then used to reproduce the latent radiation image as a visible image.
During the scanning process, a portion of the storage radiation screen is illuminated with an excitation beam and emits light that is then collected by an image acquisition optics system. Generally, the excitation beam is directed toward the screen and scans across the screen line by line. The screen is induced by an excitation beam of a radiation source to luminesce pixel by pixel. Such scanning systems are described in U.S. Pat. Nos. 4,973,134, 4,543,479, 4,582,989, and 5,635,728. In particular, U.S. Pat. No. 5,635,728 describes a rotating scanner system to efficiently read multiple storage layer radiation screens. The carousel that holds multiple storage layer radiation screens is rotated about a rotational axis, and the screens adhered to the carousel are read by an image acquisition optical system positioned adjacent the carousel. As the carousel is rotated, the screen scanning system scans over a narrow line-shaped area of the screen perpendicular to the carousel's rotational axis. The movement of the optics module in the direction parallel to the rotational axis of the carousel enables the screen scanner to scan over different narrow line-shaped areas of the screens as the carousel is rotated, thereby enabling the entire surface area of the screen to be scanned.
It is important for screen scanning systems to produce images read from the screens which have minimal artifacts and distortions generated by the scanning system. For example, artifacts such as lines or bands seriously detract from the perceived quality of the images. A need thus exists for devices and methods which can improve the image quality produced by such scanning systems.